mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.RingTheory.Trace.Basic

Goal state before:
pp: κ : Type w
A : Type u
B : Type v
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : Fintype κ
b : κ → B
P : Matrix κ κ A
⊢ (traceMatrix A (b ᵥ* (P.map ⇑(algebraMap A B))ᵀ))ᵀ = (P * traceMatrix A b * Pᵀ)ᵀ

Tactic:
← transpose_map,

Goal state after:
κ : Type w
A : Type u
B : Type v
inst✝³ : CommRing A
inst✝² : CommRing B
inst✝¹ : Algebra A B
inst✝ : Fintype κ
b : κ → B
P : Matrix κ κ A
⊢ (traceMatrix A (b ᵥ* Pᵀ.map ⇑(algebraMap A B)))ᵀ = (P * traceMatrix A b * Pᵀ)ᵀ
Module: Mathlib.FieldTheory.Galois.IsGaloisGroup

Goal state before:
pp: G : Type u_1
K : Type u_3
L : Type u_4
inst✝⁴ : Group G
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : MulSemiringAction G L
hGKL : IsGaloisGroup G K L
⊢ fixingSubgroup G ↑⊤ = ⊥

Tactic:
have := hGKL.faithful

Goal state after:
G : Type u_1
K : Type u_3
L : Type u_4
inst✝⁴ : Group G
inst✝³ : Field K
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : MulSemiringAction G L
hGKL : IsGaloisGroup G K L
this : FaithfulSMul G L
⊢ fixingSubgroup G ↑⊤ = ⊥
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: K : Type u_1
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : DecidableEq K
i : ℕ
φ : Kˣ →* K := ⋯
this : Decidable (φ = 1)
⊢ ∀ (a : Kˣ), a ^ i = 1 ↔ φ a = 1 a

Tactic:
intro x

Goal state after:
K : Type u_1
inst✝² : Field K
inst✝¹ : Fintype K
inst✝ : DecidableEq K
i : ℕ
φ : Kˣ →* K := { toFun := fun x ↦ ↑x ^ i, map_one' := ⋯, map_mul' := ⋯ }
this : Decidable (φ = 1)
x : Kˣ
⊢ x ^ i = 1 ↔ φ x = 1 x
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: K : Type u_1
inst✝¹ : Field K
inst✝ : Fintype K
i : ℕ
h : i < q - 1
hi : ¬i = 0
hiq : ¬q - 1 ∣ i
φ : Kˣ ↪ K := { toFun := fun x ↦ ↑x, inj' := ⋯ }
this : map φ univ = univ \ {0}
⊢ ∑ x, ↑x ^ i = 0

Tactic:
rw [sum_pow_units K i, if_neg]

Goal state after:
case hnc
K : Type u_1
inst✝¹ : Field K
inst✝ : Fintype K
i : ℕ
h : i < q - 1
hi : ¬i = 0
hiq : ¬q - 1 ∣ i
φ : Kˣ ↪ K := { toFun := fun x ↦ ↑x, inj' := ⋯ }
this : map φ univ = univ \ {0}
⊢ ¬q - 1 ∣ i
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: K : Type u_1
inst✝⁴ : Field K
inst✝³ : Fintype K
L : Type u_3
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Finite L
this : Fintype L
m : ℕ
lt : m < Module.finrank K L
pos : 0 < m
eq : frobeniusAlgHom K L ^ m = 1
x : L
x✝ : x ∈ univ.val
⊢ x ∈ (X ^ q ^ m - X).roots

Tactic:
mem_roots',

Goal state after:
K : Type u_1
inst✝⁴ : Field K
inst✝³ : Fintype K
L : Type u_3
inst✝² : Field L
inst✝¹ : Algebra K L
inst✝ : Finite L
this : Fintype L
m : ℕ
lt : m < Module.finrank K L
pos : 0 < m
eq : frobeniusAlgHom K L ^ m = 1
x : L
x✝ : x ∈ univ.val
⊢ X ^ q ^ m - X ≠ 0 ∧ (X ^ q ^ m - X).IsRoot x
Module: Mathlib.FieldTheory.Galois.IsGaloisGroup

Goal state before:
pp: G : Type u_1
G' : Type u_2
inst✝¹⁷ : Group G
inst✝¹⁶ : Group G'
A : Type u_5
B : Type u_6
C : Type u_7
inst✝¹⁵ : CommRing A
inst✝¹⁴ : CommRing B
inst✝¹³ : CommRing C
inst✝¹² : IsDomain C
inst✝¹¹ : Algebra A B
inst✝¹⁰ : Algebra A C
inst✝⁹ : Algebra B C
inst✝⁸ : FaithfulSMul A B
inst✝⁷ : FaithfulSMul B C
inst✝⁶ : IsScalarTower A B C
inst✝⁵ : Finite G
inst✝⁴ : Finite G'
inst✝³ : MulSemiringAction G C
inst✝² : IsGaloisGroup G A C
inst✝¹ : MulSemiringAction G' B
inst✝ : IsGaloisGroup G' A B
g : G
x : B
this✝³ : IsDomain B
this✝² : IsDomain A
this✝¹ : FaithfulSMul A C
this✝ : MulSemiringAction G (FractionRing C) := IsFractionRing.mulSemiringAction G C (FractionRing C)
this : MulSemiringAction G' (FractionRing B) := IsFractionRing.mulSemiringAction G' B (FractionRing B)
⊢ (algebraMap (FractionRing B) (FractionRing C))
      ((quotientMulEquiv G G' (FractionRing A) (FractionRing B) (FractionRing C)
            (fixingSubgroup G (Set.range ⇑(algebraMap (FractionRing B) (FractionRing C)))))
          ↑g •
        (algebraMap B (FractionRing B)) x) =
    (algebraMap C (FractionRing C)) (g • (algebraMap B C) x)

Tactic:
algebraMap_quotientMulEquiv_smul,

Goal state after:
G : Type u_1
G' : Type u_2
inst✝¹⁷ : Group G
inst✝¹⁶ : Group G'
A : Type u_5
B : Type u_6
C : Type u_7
inst✝¹⁵ : CommRing A
inst✝¹⁴ : CommRing B
inst✝¹³ : CommRing C
inst✝¹² : IsDomain C
inst✝¹¹ : Algebra A B
inst✝¹⁰ : Algebra A C
inst✝⁹ : Algebra B C
inst✝⁸ : FaithfulSMul A B
inst✝⁷ : FaithfulSMul B C
inst✝⁶ : IsScalarTower A B C
inst✝⁵ : Finite G
inst✝⁴ : Finite G'
inst✝³ : MulSemiringAction G C
inst✝² : IsGaloisGroup G A C
inst✝¹ : MulSemiringAction G' B
inst✝ : IsGaloisGroup G' A B
g : G
x : B
this✝³ : IsDomain B
this✝² : IsDomain A
this✝¹ : FaithfulSMul A C
this✝ : MulSemiringAction G (FractionRing C) := IsFractionRing.mulSemiringAction G C (FractionRing C)
this : MulSemiringAction G' (FractionRing B) := IsFractionRing.mulSemiringAction G' B (FractionRing B)
⊢ g • (algebraMap (FractionRing B) (FractionRing C)) ((algebraMap B (FractionRing B)) x) =
    (algebraMap C (FractionRing C)) (g • (algebraMap B C) x)
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: K : Type u_1
inst✝¹ : Field K
inst✝ : Fintype K
aux : X ^ q - X ≠ 0
⊢ ∀ (x : K), x ∈ (X ^ q - X).roots.toFinset

Tactic:
intro x

Goal state after:
K : Type u_1
inst✝¹ : Field K
inst✝ : Fintype K
aux : X ^ q - X ≠ 0
x : K
⊢ x ∈ (X ^ q - X).roots.toFinset
Module: Mathlib.FieldTheory.Finite.Basic

Goal state before:
pp: K : Type u_1
inst✝¹ : Field K
inst✝ : Fintype K
aux : X ^ q - X ≠ 0
x : K
⊢ x ∈ (X ^ q - X).roots

Tactic:
mem_roots aux,

Goal state after:
K : Type u_1
inst✝¹ : Field K
inst✝ : Fintype K
aux : X ^ q - X ≠ 0
x : K
⊢ (X ^ q - X).IsRoot x
Module: Mathlib.LinearAlgebra.FreeModule.Finite.Quotient

Goal state before:
pp: ι : Type u_1
R : Type u_2
M : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : AddCommGroup M
inst✝³ : Module R M
inst✝² : IsDomain R
inst✝¹ : IsPrincipalIdealRing R
inst✝ : Finite ι
N : Submodule R M
b : Basis ι R M
h : finrank R ↥N = finrank R M
this : Fintype ι
a : ι → R := smithNormalFormCoeffs b h
b' : Basis ι R M := smithNormalFormTopBasis b h
ab : Basis ι R ↥N := smithNormalFormBotBasis b h
ab_eq : ∀ (i : ι), ↑((smithNormalFormBotBasis b h) i) = smithNormalFormCoeffs b h i • (smithNormalFormTopBasis b h) i
⊢ ∀ (x : M), x ∈ N ↔ ∀ (i : ι), a i ∣ (b'.repr x) i

Tactic:
intro x

Goal state after:
ι : Type u_1
R : Type u_2
M : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : AddCommGroup M
inst✝³ : Module R M
inst✝² : IsDomain R
inst✝¹ : IsPrincipalIdealRing R
inst✝ : Finite ι
N : Submodule R M
b : Basis ι R M
h : finrank R ↥N = finrank R M
this : Fintype ι
a : ι → R := smithNormalFormCoeffs b h
b' : Basis ι R M := smithNormalFormTopBasis b h
ab : Basis ι R ↥N := smithNormalFormBotBasis b h
ab_eq : ∀ (i : ι), ↑((smithNormalFormBotBasis b h) i) = smithNormalFormCoeffs b h i • (smithNormalFormTopBasis b h) i
x : M
⊢ x ∈ N ↔ ∀ (i : ι), a i ∣ (b'.repr x) i
Module: Mathlib.RingTheory.Invariant.Basic

Goal state before:
pp: case refine_1
A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k ≃ₐ[A ⧸ P] k
f : B ⧸ Q →ₐ[A ⧸ P] k := IsScalarTower.toAlgHom (A ⧸ P) (B ⧸ Q) k
hf : Function.Injective ⇑f
τ₁ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₁ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₁ x) = ↑σ ((algebraMap (B ⧸ Q) k) x)
τ₂ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₂ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₂ x) = ↑σ.symm ((algebraMap (B ⧸ Q) k) x)
⊢ Function.LeftInverse (⇑τ₂) (↑↑τ₁.toRingHom).toFun

Tactic:
intro x

Goal state after:
case refine_1
A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k ≃ₐ[A ⧸ P] k
f : B ⧸ Q →ₐ[A ⧸ P] k := IsScalarTower.toAlgHom (A ⧸ P) (B ⧸ Q) k
hf : Function.Injective ⇑f
τ₁ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₁ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₁ x) = ↑σ ((algebraMap (B ⧸ Q) k) x)
τ₂ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₂ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₂ x) = ↑σ.symm ((algebraMap (B ⧸ Q) k) x)
x : B ⧸ Q
⊢ τ₂ ((↑↑τ₁.toRingHom).toFun x) = x
Module: Mathlib.RingTheory.Invariant.Basic

Goal state before:
pp: case refine_2
A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k ≃ₐ[A ⧸ P] k
f : B ⧸ Q →ₐ[A ⧸ P] k := IsScalarTower.toAlgHom (A ⧸ P) (B ⧸ Q) k
hf : Function.Injective ⇑f
τ₁ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₁ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₁ x) = ↑σ ((algebraMap (B ⧸ Q) k) x)
τ₂ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₂ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₂ x) = ↑σ.symm ((algebraMap (B ⧸ Q) k) x)
⊢ Function.RightInverse (⇑τ₂) (↑↑τ₁.toRingHom).toFun

Tactic:
intro x

Goal state after:
case refine_2
A : Type u_1
B : Type u_2
k : Type u_3
inst✝¹³ : CommRing A
inst✝¹² : CommRing B
inst✝¹¹ : Algebra A B
G : Type u_4
inst✝¹⁰ : Finite G
inst✝⁹ : Group G
inst✝⁸ : MulSemiringAction G B
inst✝⁷ : Algebra.IsInvariant A B G
P : Ideal A
Q : Ideal B
inst✝⁶ : Q.LiesOver P
inst✝⁵ : CommRing k
inst✝⁴ : Algebra (A ⧸ P) k
inst✝³ : Algebra (B ⧸ Q) k
inst✝² : IsScalarTower (A ⧸ P) (B ⧸ Q) k
inst✝¹ : IsDomain k
inst✝ : FaithfulSMul (B ⧸ Q) k
σ : k ≃ₐ[A ⧸ P] k
f : B ⧸ Q →ₐ[A ⧸ P] k := IsScalarTower.toAlgHom (A ⧸ P) (B ⧸ Q) k
hf : Function.Injective ⇑f
τ₁ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₁ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₁ x) = ↑σ ((algebraMap (B ⧸ Q) k) x)
τ₂ : B ⧸ Q →ₐ[A ⧸ P] B ⧸ Q
h₂ : ∀ (x : B ⧸ Q), (algebraMap (B ⧸ Q) k) (τ₂ x) = ↑σ.symm ((algebraMap (B ⧸ Q) k) x)
x : B ⧸ Q
⊢ (↑↑τ₁.toRingHom).toFun (τ₂ x) = x
Module: Mathlib.RingTheory.Norm.Basic

Goal state before:
pp: case hfg
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : Ring S
inst✝² : Algebra R S
F : Type u_6
inst✝¹ : Field F
inst✝ : Algebra R F
pb : PowerBasis R S
hE : (Polynomial.map (algebraMap R F) (minpoly R pb.gen)).Splits
hfx : IsSeparable R pb.gen
this : DecidableEq F := Classical.decEq F
⊢ ∀ (x : { x // x ∈ (minpoly R pb.gen).aroots F }), ↑x = _root_.id ↑x

Tactic:
intro x

Goal state after:
case hfg
R : Type u_1
S : Type u_2
inst✝⁴ : CommRing R
inst✝³ : Ring S
inst✝² : Algebra R S
F : Type u_6
inst✝¹ : Field F
inst✝ : Algebra R F
pb : PowerBasis R S
hE : (Polynomial.map (algebraMap R F) (minpoly R pb.gen)).Splits
hfx : IsSeparable R pb.gen
this : DecidableEq F := Classical.decEq F
x : { x // x ∈ (minpoly R pb.gen).aroots F }
⊢ ↑x = _root_.id ↑x
Module: Mathlib.RingTheory.Artinian.Ring

Goal state before:
pp: R : Type u_1
inst✝¹ : CommRing R
inst✝ : IsArtinianRing R
⊢ IsNilpotent (nilradical R)

Tactic:
by
  rw [nilradical, ← jacobson_eq_radical]
  exact isNilpotent_jacobson_bot

Goal state after:
Module: Mathlib.RingTheory.Norm.Basic

Goal state before:
pp: case refine_2
A₁ : Type u_8
B₁ : Type u_9
A₂ : Type u_10
B₂ : Type u_11
inst✝⁵ : CommRing A₁
inst✝⁴ : Ring B₁
inst✝³ : CommRing A₂
inst✝² : Ring B₂
inst✝¹ : Algebra A₁ B₁
inst✝ : Algebra A₂ B₂
e₁ : A₁ ≃+* A₂
e₂ : B₁ ≃+* B₂
he : (algebraMap A₂ B₂).comp ↑e₁ = (↑e₂).comp (algebraMap A₁ B₁)
x : B₁
this : Algebra A₁ B₂ := ((↑e₂).comp (algebraMap A₁ B₁)).toAlgebra' ?refine_1
⊢ (norm A₁) x = e₁.symm ((norm A₂) (e₂ x))

pp: case refine_1
A₁ : Type u_8
B₁ : Type u_9
A₂ : Type u_10
B₂ : Type u_11
inst✝⁵ : CommRing A₁
inst✝⁴ : Ring B₁
inst✝³ : CommRing A₂
inst✝² : Ring B₂
inst✝¹ : Algebra A₁ B₁
inst✝ : Algebra A₂ B₂
e₁ : A₁ ≃+* A₂
e₂ : B₁ ≃+* B₂
he : (algebraMap A₂ B₂).comp ↑e₁ = (↑e₂).comp (algebraMap A₁ B₁)
x : B₁
⊢ ∀ (c : A₁) (x : B₂), ((↑e₂).comp (algebraMap A₁ B₁)) c * x = x * ((↑e₂).comp (algebraMap A₁ B₁)) c

Tactic:
· let e' : B₁ ≃ₐ[A₁] B₂ := { e₂ with commutes' := fun _ ↦ rfl }
    rw [← Algebra.norm_eq_of_ringEquiv e₁ he, ← Algebra.norm_eq_of_algEquiv e']
    simp [e']

Goal state after:
case refine_1
A₁ : Type u_8
B₁ : Type u_9
A₂ : Type u_10
B₂ : Type u_11
inst✝⁵ : CommRing A₁
inst✝⁴ : Ring B₁
inst✝³ : CommRing A₂
inst✝² : Ring B₂
inst✝¹ : Algebra A₁ B₁
inst✝ : Algebra A₂ B₂
e₁ : A₁ ≃+* A₂
e₂ : B₁ ≃+* B₂
he : (algebraMap A₂ B₂).comp ↑e₁ = (↑e₂).comp (algebraMap A₁ B₁)
x : B₁
⊢ ∀ (c : A₁) (x : B₂), ((↑e₂).comp (algebraMap A₁ B₁)) c * x = x * ((↑e₂).comp (algebraMap A₁ B₁)) c
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: case succ.refine_1
S : Type u_1
inst✝¹ : CommRing S
P : Ideal S
P_prime : P.IsPrime
inst✝ : IsDedekindDomain S
hP : P ≠ ⊥
i : ℕ
ih : cardQuot (P ^ i) = cardQuot P ^ i
this : P ^ (i + 1) < P ^ i
a : S
a_mem : a ∈ P ^ i
a_notMem : a ∉ P ^ (i + 1)
f g : (c : S) → c ∈ P ^ i → S
hg : ∀ (c : S) (hc : c ∈ P ^ i), g c hc ∈ P ^ (i + 1)
hf : ∀ (c : S) (hc : c ∈ P ^ i), a * f c hc + g c hc = c
k : (c' : S ⧸ P ^ i.succ) → c' ∈ map (mkQ (P ^ i.succ)) (P ^ i) → S
hk_mem : ∀ (c' : S ⧸ P ^ i.succ) (hc' : c' ∈ map (mkQ (P ^ i.succ)) (P ^ i)), k c' hc' ∈ P ^ i
hk_eq : ∀ (c' : S ⧸ P ^ i.succ) (hc' : c' ∈ map (mkQ (P ^ i.succ)) (P ^ i)), (mkQ (P ^ i.succ)) (k c' hc') = c'
c₁' : S ⧸ P ^ i.succ
hc₁' : c₁' ∈ map (mkQ (P ^ i.succ)) (P ^ i)
c₂' : S ⧸ P ^ i.succ
hc₂' : c₂' ∈ map (mkQ (P ^ i.succ)) (P ^ i)
h : (fun c' ↦ Quotient.mk'' (f (k ↑c' ⋯) ⋯)) ⟨c₁', hc₁'⟩ = (fun c' ↦ Quotient.mk'' (f (k ↑c' ⋯) ⋯)) ⟨c₂', hc₂'⟩
⊢ c₁' = c₂'

Tactic:
← hk_eq _ hc₁',

Goal state after:
case succ.refine_1
S : Type u_1
inst✝¹ : CommRing S
P : Ideal S
P_prime : P.IsPrime
inst✝ : IsDedekindDomain S
hP : P ≠ ⊥
i : ℕ
ih : cardQuot (P ^ i) = cardQuot P ^ i
this : P ^ (i + 1) < P ^ i
a : S
a_mem : a ∈ P ^ i
a_notMem : a ∉ P ^ (i + 1)
f g : (c : S) → c ∈ P ^ i → S
hg : ∀ (c : S) (hc : c ∈ P ^ i), g c hc ∈ P ^ (i + 1)
hf : ∀ (c : S) (hc : c ∈ P ^ i), a * f c hc + g c hc = c
k : (c' : S ⧸ P ^ i.succ) → c' ∈ map (mkQ (P ^ i.succ)) (P ^ i) → S
hk_mem : ∀ (c' : S ⧸ P ^ i.succ) (hc' : c' ∈ map (mkQ (P ^ i.succ)) (P ^ i)), k c' hc' ∈ P ^ i
hk_eq : ∀ (c' : S ⧸ P ^ i.succ) (hc' : c' ∈ map (mkQ (P ^ i.succ)) (P ^ i)), (mkQ (P ^ i.succ)) (k c' hc') = c'
c₁' : S ⧸ P ^ i.succ
hc₁' : c₁' ∈ map (mkQ (P ^ i.succ)) (P ^ i)
c₂' : S ⧸ P ^ i.succ
hc₂' : c₂' ∈ map (mkQ (P ^ i.succ)) (P ^ i)
h : (fun c' ↦ Quotient.mk'' (f (k ↑c' ⋯) ⋯)) ⟨c₁', hc₁'⟩ = (fun c' ↦ Quotient.mk'' (f (k ↑c' ⋯) ⋯)) ⟨c₂', hc₂'⟩
⊢ (mkQ (P ^ i.succ)) (k c₁' hc₁') = c₂'
Module: Mathlib.RingTheory.Finiteness.NilpotentKer

Goal state before:
pp: case succ
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : Module.Finite R T
f : S →ₐ[R] T
hf₁ : Function.Surjective ⇑f
I : Ideal S
hI : RingHom.ker f = I
hf₂ : I ≤ nilradical S
hf₃ : I.FG
this : Module.Finite R (S ⧸ I)
n : ℕ
IH : Module.Finite R (S ⧸ I ^ n)
⊢ Module.Finite R (S ⧸ I ^ (n + 1))

Tactic:
let φ : (S ⧸ I ^ (n + 1)) →ₐ[S] S ⧸ I ^ n :=
      Ideal.Quotient.factorₐ _ (Ideal.pow_le_pow_right n.le_succ)

Goal state after:
case succ
R : Type u_1
S : Type u_2
T : Type u_3
inst✝⁵ : CommRing R
inst✝⁴ : CommRing S
inst✝³ : CommRing T
inst✝² : Algebra R S
inst✝¹ : Algebra R T
inst✝ : Module.Finite R T
f : S →ₐ[R] T
hf₁ : Function.Surjective ⇑f
I : Ideal S
hI : RingHom.ker f = I
hf₂ : I ≤ nilradical S
hf₃ : I.FG
this : Module.Finite R (S ⧸ I)
n : ℕ
IH : Module.Finite R (S ⧸ I ^ n)
φ : S ⧸ I ^ (n + 1) →ₐ[S] S ⧸ I ^ n := Ideal.Quotient.factorₐ S ⋯
⊢ Module.Finite R (S ⧸ I ^ (n + 1))
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: S : Type u_1
inst✝² : CommRing S
inst✝¹ : IsDedekindDomain S
inst✝ : Free ℤ S
I J : Ideal S
⊢ cardQuot (I * J) = cardQuot I * cardQuot J

Tactic:
by
  let b := Module.Free.chooseBasis ℤ S
  have : Infinite S := Infinite.of_surjective _ b.repr.toEquiv.surjective
  exact UniqueFactorizationMonoid.multiplicative_of_coprime cardQuot I J (cardQuot_bot _ _)
      (fun {I J} hI => by simp [Ideal.isUnit_iff.mp hI, Ideal.mul_top])
      (fun {I} i hI =>
        have : Ideal.IsPrime I := Ideal.isPrime_of_prime hI
        cardQuot_pow_of_prime hI.ne_zero)
      fun {I J} hIJ => cardQuot_mul_of_coprime <| Ideal.isCoprime_iff_sup_eq.mpr
        (Ideal.isUnit_iff.mp
          (hIJ (Ideal.dvd_iff_le.mpr le_sup_left) (Ideal.dvd_iff_le.mpr le_sup_right)))

Goal state after:
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: case mp
S : Type u_1
inst✝³ : CommRing S
inst✝² : IsDedekindDomain S
inst✝¹ : Free ℤ S
inst✝ : Module.Finite ℤ S
I : Ideal S
hI : absNorm I = 0
⊢ I ≤ ⊥

Tactic:
intro x

Goal state after:
case mp
S : Type u_1
inst✝³ : CommRing S
inst✝² : IsDedekindDomain S
inst✝¹ : Free ℤ S
inst✝ : Module.Finite ℤ S
I : Ideal S
hI : absNorm I = 0
x : S
⊢ x ∈ I → x ∈ ⊥
Module: Mathlib.RingTheory.Ideal.Norm.AbsNorm

Goal state before:
pp: S : Type u_1
inst✝³ : CommRing S
inst✝² : IsDedekindDomain S
inst✝¹ : Free ℤ S
inst✝ : Module.Finite ℤ S
I : Ideal S
hI : I ≠ ⊥
⊢ (toAddSubgroup I).FiniteIndex

Tactic:
by
  rwa [AddSubgroup.finiteIndex_iff, ← absNorm_eq_index, Ne, absNorm_eq_zero_iff]

Goal state after:
Module: Mathlib.GroupTheory.Submonoid.Inverses

Goal state before:
pp: M : Type u_1
inst✝ : Monoid M
S : Submonoid M
hS : S ≤ IsUnit.submonoid M
⊢ S ≤ S.leftInv.leftInv

Tactic:
intro x

Goal state after:
M : Type u_1
inst✝ : Monoid M
S : Submonoid M
hS : S ≤ IsUnit.submonoid M
x : M
⊢ x ∈ S → x ∈ S.leftInv.leftInv
Module: Mathlib.GroupTheory.Submonoid.Inverses

Goal state before:
pp: M : Type u_1
inst✝ : CommMonoid M
S : Submonoid M
hS : S ≤ IsUnit.submonoid M
⊢ Function.LeftInverse (fun x ↦ ⟨↑(IsUnit.unit ⋯)⁻¹, ⋯⟩) (↑S.fromCommLeftInv).toFun

Tactic:
intro x

Goal state after:
M : Type u_1
inst✝ : CommMonoid M
S : Submonoid M
hS : S ≤ IsUnit.submonoid M
x : ↥S.leftInv
⊢ (fun x ↦ ⟨↑(IsUnit.unit ⋯)⁻¹, ⋯⟩) ((↑S.fromCommLeftInv).toFun x) = x
Module: Mathlib.Topology.JacobsonSpace

Goal state before:
pp: X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
hf : Function.Injective f
hf' : Continuous[inst✝¹, inst✝] f
⊢ f ⁻¹' closedPoints Y ⊆ closedPoints X

Tactic:
intro x

Goal state after:
X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
hf : Function.Injective f
hf' : Continuous[inst✝¹, inst✝] f
x : X
⊢ x ∈ f ⁻¹' closedPoints Y → x ∈ closedPoints X
Module: Mathlib.Topology.JacobsonSpace

Goal state before:
pp: X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : JacobsonSpace X
S : Set X
hS : IsLocallyClosed S
⊢ S ⊆ closure[inst✝¹] (S ∩ closedPoints X)

Tactic:
intro x

Goal state after:
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : JacobsonSpace X
S : Set X
hS : IsLocallyClosed S
x : X
⊢ x ∈ S → x ∈ closure[inst✝¹] (S ∩ closedPoints X)
Module: Mathlib.Topology.JacobsonSpace

Goal state before:
pp: X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : JacobsonSpace X
S : Set X
hS : IsLocallyClosed S
x : X
hx : x ∈ S
H : x ∉ closure[inst✝¹] (S ∩ closedPoints X)
y : X
hy₃ : y ∈ closedPoints X
hy₁ : y ∈ S
hy₂ : y ∉ closure[inst✝¹] (S ∩ closedPoints X)
⊢ False

Tactic:
exact hy₂ (subset_closure ⟨hy₁, hy₃⟩)

Goal state after:
Module: Mathlib.Topology.JacobsonSpace

Goal state before:
pp: X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
f : X → Y
hf : IsOpenEmbedding f
inst✝ : JacobsonSpace Y
⊢ closedPoints X ⊆ f ⁻¹' closedPoints Y

Tactic:
intro x

Goal state after:
X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
f : X → Y
hf : IsOpenEmbedding f
inst✝ : JacobsonSpace Y
x : X
⊢ x ∈ closedPoints X → x ∈ f ⁻¹' closedPoints Y
Module: Mathlib.Topology.JacobsonSpace

Goal state before:
pp: X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : JacobsonSpace X
h : (closedPoints X).Finite
this : closedPoints X = Set.univ
inst : Finite X
s : Set X
⊢ IsOpen[inst✝¹] s

Tactic:
rw [← isClosed_compl_iff, ← sᶜ.biUnion_of_singleton]

Goal state after:
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : JacobsonSpace X
h : (closedPoints X).Finite
this : closedPoints X = Set.univ
inst : Finite X
s : Set X
⊢ IsClosed[inst✝¹] (⋃ x ∈ sᶜ, {x})
Module: Mathlib.Topology.JacobsonSpace

Goal state before:
pp: case inr
X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
f : X → Y
inst✝ : JacobsonSpace X
S : Set X
hS : IsLocallyClosed S
hf₁ : Continuous[inst✝², inst✝¹] f
hf₂ : IsClosedMap f
hfS : (f '' S).Finite
hS'' : S.Nonempty
hS' : IsIrreducible S
H₁ : IsIrreducible (S ∩ closedPoints X)
⊢ (f '' closure[inst✝²] S).Subsingleton

Tactic:
have H₂ : f '' (S ∩ closedPoints X) ⊆ closedPoints Y := by
    rintro _ ⟨x, hx, rfl⟩; simpa using hf₂ _ hx.2

Goal state after:
case inr
X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
f : X → Y
inst✝ : JacobsonSpace X
S : Set X
hS : IsLocallyClosed S
hf₁ : Continuous[inst✝², inst✝¹] f
hf₂ : IsClosedMap f
hfS : (f '' S).Finite
hS'' : S.Nonempty
hS' : IsIrreducible S
H₁ : IsIrreducible (S ∩ closedPoints X)
H₂ : f '' (S ∩ closedPoints X) ⊆ closedPoints Y
⊢ (f '' closure[inst✝²] S).Subsingleton
Module: Mathlib.RingTheory.LocalRing.Length

Goal state before:
pp: case pos
A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁹ : CommRing A
inst✝⁸ : CommRing B
inst✝⁷ : IsLocalRing A
inst✝⁶ : IsLocalRing B
inst✝⁵ : Algebra A B
inst✝⁴ : IsLocalHom (algebraMap A B)
inst✝³ : AddCommGroup M
inst✝² : Module A M
inst✝¹ : Module B M
inst✝ : IsScalarTower A B M
h : IsFiniteLength B M
s : CompositionSeries (Submodule B M)
hs_bot : RelSeries.head s = ⊥
hs_top : RelSeries.last s = ⊤
⊢ length A M = ↑s.length * length (ResidueField A) (ResidueField B)

Tactic:
suffices ∀ k, length A (s k) = k * Module.length (ResidueField A) (ResidueField B) by
      rw [← Fin.val_last s.length, ← this, ← RelSeries.last, hs_top]
      exact length_top.symm

Goal state after:
case pos
A : Type u_1
B : Type u_2
M : Type u_3
inst✝⁹ : CommRing A
inst✝⁸ : CommRing B
inst✝⁷ : IsLocalRing A
inst✝⁶ : IsLocalRing B
inst✝⁵ : Algebra A B
inst✝⁴ : IsLocalHom (algebraMap A B)
inst✝³ : AddCommGroup M
inst✝² : Module A M
inst✝¹ : Module B M
inst✝ : IsScalarTower A B M
h : IsFiniteLength B M
s : CompositionSeries (Submodule B M)
hs_bot : RelSeries.head s = ⊥
hs_top : RelSeries.last s = ⊤
⊢ ∀ (k : Fin (s.length + 1)), length A ↥(s.toFun k) = ↑↑k * length (ResidueField A) (ResidueField B)
Module: Mathlib.RingTheory.RamificationInertia.Inertia

Goal state before:
pp: S : Type u_1
inst✝³ : CommRing S
q : Ideal S
R : Type u_2
inst✝² : CommRing R
inst✝¹ : Algebra R S
hq : q.IsPrime
inst✝ : Module.Finite R S
this : Algebra (Localization.AtPrime (under R q)) (Localization.AtPrime q) :=
  Localization.AtPrime.algebraOfLiesOver (under R q) q
⊢ 0 < q.inertiaDeg R

Tactic:
inertiaDeg_def

Goal state after:
S : Type u_1
inst✝³ : CommRing S
q : Ideal S
R : Type u_2
inst✝² : CommRing R
inst✝¹ : Algebra R S
hq : q.IsPrime
inst✝ : Module.Finite R S
this : Algebra (Localization.AtPrime (under R q)) (Localization.AtPrime q) :=
  Localization.AtPrime.algebraOfLiesOver (under R q) q
⊢ 0 < Module.finrank (under R q).ResidueField q.ResidueField